Rampant misuse of antibiotics

Drug-resistant TB

Multidrug-resistant TB (MDR TB) is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs.

Extensively drug resistant TB (XDR TB) is a rare type of MDR TB that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs, such as amikacin, kanamycin, or capreomycin).

"There are several drugs used to treat TB," says Lorraine Rebello, medical services manager at the MSF TB and HIV clinic in Mumbai.

"But when two of the primary drugs that are essential to treating TB - rifampicin and isoniazid - are no longer killing the TB bacteria, then the patient has drug-resistant TB."

The Indian government's Revised National TB Control Program aims to provide free TB treatment to every tuberculosis patient in the country.

But the WHO says out of the estimated 64,000 drug-resistant cases in India in 2012, only 16,588 were diagnosed.

Lorraine Rebello puts the rise in cases she has seen down to a number of factors.

What could happen is progressively multi-drug resistant TB takes over from normal tuberculosisDr Mario Raviglione, Director, Global TB programme at the World Health Organization

"We have a huge unregulated private sector," she says.

"We have doctors who are not properly medically qualified, like Ayurvedic doctors who are treating drug-resistant TB.

"They probably don't have the knowledge to treat the condition, but they prescribe a cocktail of drugs.

"Some patients are even going to pharmacies without prescription and buying drugs over the counter. So we are seeing a rampant misuse of antibiotics."

Dr Mario Raviglione, director of the WHO's Global TB programme, describes the situation as a public health crisis.

"What could happen is progressively multi-drug resistant TB takes over from normal tuberculosis.

"If this happens not only would millions of patients potentially die of this form of TB, but if I look at it from an economic perspective the cost of dealing with millions of potential cases is enormous."

He describes the fact that 80% of multi-drug resistant TB cases around the world are not being treated as a "ticking time bomb".

"Killing you slowly"

Dr Ruth Mcnerny, senior lecturer at the London School of Tropical Medicine, who works with TB charity TB Alert, says: "We're just silently watching this epidemic unfold and spread before our eyes.

TB treatment in developing countries

Normal TB treatment takes at least six months to treat and costs around $50 (£30)

Multidrug-resistant TB treatment can take at least two years and costs around $2,500 (£1,500)